Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Zhang Dissertation final 2.0.pdf (13.27 MB)

ETD Abstract Container

Abstract Header

Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates

Zhang, Yue
http://rave.ohiolink.edu/etdc/view?acc_num=osu1431069679

Abstract Details

2015, Doctor of Philosophy, Ohio State University, Evolution, Ecology and Organismal Biology.
Multituberculates are an extinct mammalian group that has its geological time span from at least the Late Jurassic to the latest Eocene, with fossils on all continents except Antarctica. Before the K-Pg boundary, in most North American Late Cretaceous mammalian faunas, multituberculates outnumbered eutherians and metatherians in both abundance and species richness. After the K-Pg boundary, the taxonomic diversity of multituberculates was succeeded by placental mammals. Multituberculates have unique dentition morphology differing from all extant mammals. Despite the importance of multituberculates in the study of mammalian evolution, much less is known about this enigmatic mammalian lineage compared to our knowledge of therian mammals. My dissertation mainly discusses the phylogenetics of Neoplagiaulacidae, the taxonomically richest family of multituberculates, and reconstructs the diets of cimolodontans (multituberculates from the Late Cretaceous to Paleogene) based on analyses of tooth wear, cusp charpness, and tooth size proportions. My phylogenetic study of neoplagiaulacids use a novel method proposed by me, the standardized character weighting approach. In this method, the variable range of character steps in each different character is set to the same scale. This new method has great superiority compared to the traditional parsimony method, in eliminating character state delimitation problem, finding the most balanced phylogenetic signals among conflicts, and not losing any evidence. The phylogenetic analysis of neoplagiaulacids reveals the evolution pattern of neoplagiaulacids on both large and small scales. The result shows that different lineages had different pathways of morphological specialization and a tendency of convergent evolution in acquiring larger ultimate lower premolar (p4). The result also indicates that ptilodontids were most likely derived from Parectypodus armstrongi. For the diet reconstruction of cimolodontans using multiple lines of evidence, the tooth wear patterns of the ultimate premolars (p4 and P4) are analyzed to infer the tooth function and chewing mechanism, the cusp sharpness on molars are linked with the physical perporty of food items, and the tooth size proportions are used to infer the developmental mode, which further reveals diet signal. The result indicates that the method presented here using combined evidence is robust in inferring the diet of cimolodontans. In the end, the tooth size proportions of multituberculates are compared to that of placental mammals, demonstrating that the lesser radiation and subsequent declination of multituberculates following the K-Pg boundary is correlated with less developmental plasticity of multituberculate teeth compared to that of placental mammals.
John Hunter (Advisor)
William Ausich (Committee Member)
John Freudenstein (Committee Member)
Debbie Guatelli-Steinberg (Committee Member)
Paleontology

Recommended Citations

Citations

  • Zhang, Y. (2015). Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1431069679

    APA Style (7th edition)

  • Zhang, Yue. Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates. 2015. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1431069679.

    MLA Style (8th edition)

  • Zhang, Yue. "Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates." Doctoral dissertation, Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1431069679

    Chicago Manual of Style (17th edition)

osu1431069679
1,076
© 2015, some rights reserved.Creative Commons License Phylogenetics of Neoplagiaulacidae (Multituberculata, Mammalia), and Diet Reconstruction on Cimolodontan Multituberculates by Yue Zhang is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by The Ohio State University and OhioLINK.